Liner for refrigeration units



Sept- 21, 1965 w. R. LINDERSMITH ETAL 3,206,945

LINER FOR REFRIGERATION UNITS 2 Sheets-SheerI 1 Filed Dec. 6, 1965 f-Bl EN a

/NVENTORS R. L//vDERsM/TH EAR/ v HoPK//vs STEPHEN scf-/AFFER WILL /AM ATTORNEYS sept. 21, 1965 W. R. LINDERSMITH ETAL LINER FOR REFRIGERATION UNITS Filed Dec. 6, 1963 2 Sheets-Sheet 2 lll! /N VE /V TOS.

WILL/AM R. LINDER SMITH EARL. V HOPKINS STFPHEA/ S'CH/IF'FER mum ATTORNEYS United States Patent O 3,206,946 LINER FOR REFRIGERATION UNITS William R. Lindersmith, Earl V. Hopkins, and Stephen Schaffer, Marysville, Yuba County, Calif.; said Lindersmith assignor to Mid-Cal Plastics, Inc., Marysville,

Calif., a corporation of California Filed Dec. 6, 1963, Ser. No. 328,670 4 Claims. (Cl. 62-407) This invention relates to a new and improved type of liner for refrigerated railroad cars, trucks and the like and more specifically to a liner that not only spaces the lading out from the compartment walls but provides forced cold air circulation for heat conduction.

It has long been the practice in the design of refrigerated vans and cars to prevent the lading from making contact with the compartments insulated walls so that spaces are created between the lading and the wall to enhance cold air circulation by convection. In various prior art devices this has 'been achieved by the use of different types of corrugated surfaces, vertical spacer strips, or spacer blocks placed at intervals along the compartments inner walls. However, none of these devices has provided means whereby cold -air is forced circulated in a -controlled manner to -achieve conductive heat transfer, particularly in the upper portions of the compartment, before circulation by convection between the lading and the liner.

Thus, it is an object of the present invention to provide a liner comprising a series of reinforced, corrugated, panel-s in -which the corrugations of each panel run in a substantially vertical, generally sinusoidal, and continuous S-shaped path forming ducts for conductive heat transfer and forced ventilation of cold air from ceiling vents; the lower ends of the ducts terminate just below the raised structure which supports the lading thus causing the cold lair to continue circulation by convective means between the lading and the yspaces between the corrugations.

Another feature of the present inven-tion is the shape of the liner 4corrugations to avoid damage to either the lading containers or the liner themselves during periods when the mobile refrigerated units are either accelerated, stopped, or bumped Prior art attempts to solve this problem have included Vertical corrugations, which have proved vulnerable to damage vby catching the corresponding vertical edges of the lading containers; the use of jagged, zig-zag lines of corrugation, which also show a tendency to catch the lading at the points Where the corrugations form sharp angles; the use of straight lbut non-vertical corrugations; and staggered spacer blocks protruding out from the side Walls of the compartment. Although the last two mentioned solutions tend to avoid the problem of liner or lading damage, neither can provide internal ducts for forced cold air circulation 4and heat transfer by conduction over an entire compartment Wall.

Thus an advantage of the present inventions feature of forming hollow corrugations in a continuous, smooth, curved, and substantially Vertical path is not only the avoidance of vertical or sharp, zig-zag corner contact with the lading, which may cause damage, but also the provision of internal ducts of ideal shape for heat conduction and the transport of the forced circulated cold air.

Still vanother feature of the invention stemming from the continuous curved shape of the ducts is the extended path-s that are formed for the cold air to travel so that heat conduction occurs over a maximum period of time and duct length. This further enhances the cooling efliciency of the system; cold air is exposed to efcient heat exchange while traveling through the internal, elongate, ducts including periods-When the `forced air is coldestin the upper regions of the refrigeration compartment ICC where the surrounding compartment air to 'be cooled is warmest. At this point of greatest temperature difference, maximum heat transfer with highest efficiency occurs, a feature not achieved by conventional techniques which depend upon convection alone in the air spaces between the corrugations and lading. Such convection mainly results in cold air concentrating at the floor region Where little effective cooling occurs.

Another advantage of the present invention is that by the use of the ducts formed by the corrugations, as well as the spacing between ducts for cold air circulation, overall cooling and insulative capability is achieved in less total thickness of Wall and liner than is possible with less eiiective conventional techniques. This over-all capability is enhanced in the inventions present embodiment `by the use of reinforced plastics that not only reduce the -actual liner thickness but make smooth curve corrugations practicable using economic molding techniques. Acco-rdingly, less pay load space is taken up 'by insulation and liner resulting in greater revenues per refrigerated unit.

Other objects of the present invention will become apparent upon reading the following specification and referring to the accompanying drawings in which similar characters of reference represent corresponding parts in each of the several views.

Turning now to the drawings:

FIG. 1 `shows a typical cross section of a motorized refrigerated trailer van with the liner lof this invention in operating position.

FIG. 2 is a detail of a partial side elevation of a liner in position as seen along the line 2-2 indicated in FIG. 1.

FIG. 3 is a detail of a typical liner panel shown in isometric View.

FIG. 4 is an end view indicated by line 4 4 in FIG. 2.

FIG. 5 is a cross-sectional view as seen along the line 5-5 in FIG. 2.

The present embodiment of the invention can best be understood in terms of an instal-lation as indicated generally fby LFIG. l. A :typical -mobile refrigeration unit is shown there 4in partial late-ral elevational section. A roof and ceiling section is indicated generally at A while insulated wall section and ibase floor are shown at B and C, respectively. Floor racks and pallets indica-ted generally at D provide .supporting structure for typical lading indicated generally at E.

Between ceiling surface 12 and exterior insulated roo-f surface 13 there is a plenum 14 through which cold air produced by conventional refrigeration means, or ice, is forced ventilated down through 4a plurality of vents 16 in the direction of arrow 17.

A plurality of wall liners as indicated generally at -18 `are attached directly adjacent to wall insulation 19 throughout the interior of the refrigeration unit compartrnent.

The liners themselves as shown in FIGS. 3, 4 and 5 comprise Itwo basic elements, =backing 20 and a corrugated face piece indicated generally at 21 formed from reinforced plastic or the like.

,Face piece 21 is molded to provide a plurality of curved ducts or corrugations 22 of uniform cross sec-tion except for the flared region 23, best seen in FIG. 4, found at either extreme of said `ducts to enhance the recept-ion of the forced vented cold air indicated above by arrows 17, FIGS. l and 2. End ducts 24 and 26 with irregularly flared ends 27 and 28, respectively, as seen in FIGS. 2, 3 and 4, complete a given corrugated face panel. Walls 29 of each of the ducts 22 seen in FIG. 5 form .a gradual smooth S-shaped or sinusoidal curve running in a substantially vertical direction as shown in FIG. 2. Similarly, walls 31 form the opposite sides of the duct in parallel spaced relationship to each of 29. End ducts 24 and 26 have one 4str-aight wall each, 32 and 33, respectively, which form the vertical ends of each of the corrugated face panels.

Thus cold air as indicated at arrow 17 is conducted vertically downward through ducts 22, 24 and 26, the tops of the liners being closed off from the rest of the interior of the compartments by skirt portion 34 in FIG. l, thus enhancing said flow of air indicated lby arrow 17.

Upon being forced through the sinusoidal shaped ducts on the interior of the reinforced plastic corrugations, the cold air act-s to cool by conduction the -adjacent outside air in contact with the plastic liners, hence effectuating maximum heat transfer throughout the upper regions of lthe refrigeration uni-t compartment where the less dense warm .air rises and creates greater need for effective cooling. Moreover, the forced air upon immediately entering the ducts at flared ends 23 effectuates the greatest degree of heat transfer and resultan-tcooling because of the maximum temperature difference between the cold yair withi in the ducts and the air in the adjacent region of the refrigerated compartment.

Upon arriving at the bottom of each of the separate panels, the cold air exits at similar liares 23, 27 and 28l located at the bottom of the panels, said air currents indicated by larrow 36 in FIG. 1.

The suboor and pallets indicated generally at D comprise a slotted space framework of vertical pieces 37 and horizontal boards 38 which rest on the base floor surface 39. Directly on top of the subiioor structure are typical load pallets 41 which directly support the lading indicated generally at E. T-he sublioor st-ructure and load pallets are arranged in conventional manner forming a lad-ing support which permits the direct ow of .air between said pallets and subfloor for further air circulation as indicated by arrows 42, 43, 44, 46 and 47, FIG. 1.

Even with lading containers indicated generally at E butted up directly aga-inst panel liners 18, spaces 48, .as seen in IFIG. 2, between adjacent corrugations, and spaces 50, between adjacent panels, remain unobstructedand capable of permitting circulation of .air by convection as indicated by arrows 51.

Although the foregoing invention has been described in some detail by way of illustration and example for purposes of clarity of understanding, it is understood that certain changes and modifications may be practiced within the spirit of the invention and scope of the appended claims.

In the claims: l

l1. In a refrigerated compartment, including a plenum between the roof and ceiling wherein cold air is forced ventilated, the combination comprising: A plurality of vents spaced Ialong the upper portion of said compartment adjacent to the intersection of at least some of the walls and ceiling and in fluid communication with said plenum; wall panels for mounting against the walls of the compartment, said panels each comprising a backing for securing against the compartment walls, a corrugated facing attached to said backing, corrugations of -said facing forming a series of substantially vertical ducts extending outwardly from said backing with the duct faces substantially parallel to said backing and the duct sides parallel to each other and formed in a uniform, smooth, repetitive, waved curve extending Ibetween the ceiling and floor of s-aid compartment; upper ends of said corrugation-s forming openings located immediately opposite and in fluid communication with said vents; skirt portions extending downward from the ceiling and spaced out from adjacent wall portions a distance equal to the ythickness of said panels Iand extending downward a distance sufficient to overlap said upper ends of said corrugations.

2. In a refrigeration compartment including insulation disposed inwardly of the walls of said compartment, wall liners each comprising a first panel immediately adjacent to said insulation; a second panel secured to said rst panel, said second panel formed in a series of corrugations substantially vertical to the floor of said compartment; ducts formed by said corrug-ations; upper ends of said ducts for-med wider than the 'body portions of said ducts wherein flared shaped openings are formed, each said opening 'being in substantially tangential contact with an adjacent opening; means causing cold .air into said upper ends whereby the cold air is transported through said ducts.

3. In a mobile refrigerated unit, the combination comprisingz a `liner Afor the walls of said compartment; a corrugated surface of said liner; said corrugated surface forming protrusions extending substantially from floor to ceiling of said compartment, each of the prot-rusions shaped to describe a continuous, smooth, repetitive S- shaped curve in space parallel relation to each adjacent protrusion whereby vertical edges of ladingtransported in said unit contacts no single protrusion continuously or at a sharp angle.

4. In a refrigerated compartment utilizing supports vertically spaced above the oor of said compartment to support lading to :be refrigerated, the combination comprising dirst panels immediately adjacent to the'walls of said compartment; second panels mounted on said rst panels; a series of substantially vertical, smooth, S-shaped, corrugations formed in said second panels; a plurality of Vents spaced in the upper portion of said compartment; la iirst open end in each of said vertical corrugations in diuid communication with each of said vents; a second open end of each said vertical corrugations .at an elevation below said supports whereby cold air is caused to, circulate from each of said vents into one said first open end and thence through one of said corrugations, egressing at the second o-pen end of said corrugation beneath the lading to be refrigerated.

References Cited by the Examiner UNITED STATES PATENTS 1,256,162 2/18 Patee 62--405 2,184,819 12/39 Sisson 62-418 2,305,141 12/42 Crede 62-416 2,517,699 8/ 50 OConnor 105-423 2,641,449 6/53 Antony 98--31 2,740,266 4/56 Kesling 62-407 `42,791,463 5/ 57 Levitt 296-28 2,882,701 4/ 59 Nelson 62-405 WILLIAM I. WYE, Primary Examiner.

ROBERT A. OLEARY, Examiner. 

1. IN A REFRIGERATED COMPARTMENT, INCLUDING A PLENUM BETWEEN THE ROOL AND CEILING WHEREIN COLD AIR IS FORCED VENTILATED, THE COMBINATION COMPRISING: A PLURALITY OF VENTS SPACED ALONG THE UPPER PORTION OF SAID COMPARTMENT ADJACENT TO THE INTERSECTION OF AT LEAST SOME OF THE WALLS AND CEILING AND IN FLUID COMMUNICATION WITH SAID PLENUM; WALL PANELS FOR MOUNTING AGAINST THE WALLS OF THE COMPARTMENT, SAID PANELS EACH COMPRISING A BACKING FOR SECURING AGAINST THE COMPARTMENT WALLS, A CORRUGATED FACING ATTACHED TO SAID BACKING, CORRUGATIONS OF SAID FACING FORMING A SERIES OF SUBSTANTIALLY VERTICAL DUCTS EXTENDING OUTWARDLY FROM SAID BACKING WITH THE DUCT FACES SUBSTANTIALLY PARALLEL TO SAID BACKING AND THE DUCT SIDES PARALLEL TO EACH OTHER AND FORMED IN A UNIFORM, SMOOTH 